================================================================================

Array(UnbufferedChannel((Nil | Exception+))) trace:

  /usr/local/Cellar/crystal-lang/0.7.4/src/enumerable.cr:227

          return elem if yield elem
                               ^~~~

  /usr/local/Cellar/crystal-lang/0.7.4/src/enumerable.cr:226

        each do |elem|
                 ^~~~

  macro macro_4596930912 (in /usr/local/Cellar/crystal-lang/0.7.4/src/tuple.cr:163):2

          yield self[0]
                    ^